Hot air heating system



Nov. 21, 1961 F. DIBERT HOT AIR HEATING SYSTEM 2 Sheets-Sheet 1 Filed Oct. 13. 1958 lllllllllllllllllllllll n,

ATTORNEY Nov. 21, 1961 Filed OCt. 13. 1958 F. DIBERT HOT AIR HEATING SYSTEM J 4+9 ,8. 1g 62 as l I l I I 2 Sheets-Sheet 2 67 29 g mi IN VEN TOR.

Fred .Diberi ATTORNEY United States Patent 3,009,643 HOT AIR HEATING SYSTEM Fred Dibert, 2617 Prospect St., Flint, Mich. Filed Oct. 13, 1958, Ser. No. 766,770 6 Claims. (Cl. 237-55) This invention relates to hot air heating systems that are confined within building enclosures for heating the interior of said enclosures, and more particularly to systems of the general type as that disclosed in my co-pending patent application, Serial No. 671,888, filed July 15, 1957, now Patent No. 2,962,218, granted Nov. 29, 1960, wherein fresh outside air is supplied to the system so as to replenish air to the enclosure for air consumed by burners and air exhausted through stacks by draft diverters, clothes driers, ventilator fans, etc.

It is an established fact that sub-normal air pressure within a dwelling causes cold outside air to rush into the dwelling upon the opening of a door, and that upon raising the air pressure within the dwelling above that of outside atmospherical pressure the opening of a door will cause warm air from within the dwelling to pass quickly out through the door opening. Therefore, equalizing of air pressure within the dwelling with that of the outside atmospherical pressure would cause considerably less displacement of air at and around openings in the dwelling, which naturally would result in less drafts and a great economy in the consumption of fuel. This is especially so when maintaining a selected temperature in the dwelling with the use of a thermostat furnace control.

It is, therefore, an object of the present invention to provide a novel and improved duct construction and arrangement for supplying outside air to a hot air heating system for replenishing air consumed in and exhausted from the interior of a dwelling.

Another object of the invention is to provide a heating system wherein the above mentioned supply of outside fresh air is heated in a novel and improved manner prior to its entrance into the heating system and mixed with air to be circulated through the dwelling.

' A further object of the invention is to provide in a heating system of the character set forth, an outside air preheater in the form of a relatively short cross duct into which an open end portion of the outside air supply pipe extends, said duct bypassing regular circulation of air through a dwelling by having its opposite end portions in communication with the hot air flow side and cooler air return side of a heater and in amanner so that a small quantity of hot air from the flow side of the heater is first circulated around the outer side of the end portion of the outside air supply pipe and then mixed with the outside air from the open end of the air supply pipe before said mixture of air enters the return side of the heater for further heating by said heater.

' A further object of the invention is the provision in a heating system as above set forth, of a diffusion element in the path of exit of outside air from the open end of the outside air supply pipe so as to more completely mix the outside air with heated air prior to the entrance of mixed air into the return air side of the heater.

A still further object of the invention is to provide in a heating system as outlined above, a damper in the outside air supply pipe for controlling the flow of outside air through said pipe, and a thermostat in the hot air passageway surrounding said pipe for controlling the position of said damper, there being a manual adjustment to said thermostat so as to change the position of the damper relative to the temperature at the thermostat.

Still another object'of the invention is to provide a novel duct unit of the above indicated character for the attachment of an outside air supply pipe thereto and for Patented Nov. 21, 1961 convenient and efiicient attachment thereof to existing hot air heating systems.

It is also an object of the invention to provide a novel and improved duct unit as set forth above which is simple and substantial in construction, economical to manufacture, and thoroughly eflicient and practical in use.

Other and further objects of the invention will become apparent from a reading of the following specification taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevation and sectional view through a forced air furnace showing air flow and return ducts connected thereto, and showing the improved air pressure equalizing improvement installed thereon;

FIGURE 2 is a horizontal section through the air flow and return ducts showing the pressure equalizer in plan;

FIGURE 3 is an enlarged longitudinal section taken on a horizontal line 33 of FIGURE 1;

FIGURES 4, 5 and 6 are vertical cross sections taken on lines 4-4, 55, and 6--6, respectively, in FIG- URE 3;

FIGURE 7 is a fragmentary section taken on line 77 of FIGURE 6; v

FIGURE 8 is a side elevation and sectional view of a gravity warm air furnace showing the improved air pressure equalizing improvement elongated and installed on the furnace;

FIGURE 9 is a fragmentary vertical section taken on line 9--9 of FIGURE 8 showing the pressure equalizer in elevation; and

FIGURE 10 is a vertical section through a central heating pipeless furnace showing the improved pressure equalizing improvement in elevation.

Referring now more specifically to the accompanying drawings, wherein like numerals designate similar parts throughout the various views, attention is directed first to FIGURE 1, wherein there is indicated by the numeral 12 a forced air heating furnace which, for the purpose of illustration, is shown as being of a gas-fired type, and as having a hot air compartment 13 with a heat exchanger 14 therein and a cold air return compartment 15 enclosing filters 16 and a blower 17. The blower 17, while being located in the lower portion of the return air compartment 15 and receiving its intake of air from said compartment, discharges its air into the hot air compartment 13 through an open end of a tangentially projecting portion 18 of the blower housing 19. A partition wall 20 that divides the return air compartment 15 from the hot air compartment 13 has an opening therein through which the tangentially projecting portion 18 extends. A main hot air flow duct 21 and a main cool air return duct 22 are shown as connected to the upper portions of the hot air compartment 13 and return air compartment 15, respectively, and it is through these ducts that air is circulated to and fnorn different rooms of a dwelling, not shown, by the blower 17.

The preceding detail description, for all practical purposes, defines the same general construction as that now commonly employed in forced hot air heating systems, and it is to a construction and arrangement of elements of this character that slight modifications have been made and parts added which produce a different result and which constitute the subject matter of the present invention.

Extending across and to one side of, the walls 23 and 24 of the ducts 21 and 22, which are substantially square in cross section, is a cross duct 25 also substantially square in cross section, but of considerably less cross sectional size than the ducts 21 and 22. The smaller-duct 25 has its opposite end portions in communication with the ducts 21 and 22,. as shown by the numerals 26 and 3 27 in FIGURES 2 and 3, there being a short cylindrical pipe section 28 of still further reduced size utilized to communicate one end portion of the cross duct 25 with the hot air flow duct 21 and a right angled end 29 to effect communication of its opposite end with the cool air return duct 22 The short cyiindrical pipe section 23 projects to the same side of the duct 25 as that to which the angled end 29 is turned, is bodily carried by the duct 25, and extends through an opening 30 in the wall 23 and into the duct 21, while the open right angled end 29 registers with an opening 31 in the wall 24 of the duct 22. It, therefore, can be seen that a small quantity of hot air from the hot air flow duct 21 is bypassed to the cool air return duct 22 by the cross duct 25, which is for a purpose to be set forth as the description proceeds.

On the intake end of the cross duct 25 there is an end wall 32 provided with a circular hole 33 through which extends a cylindrical pipe section or conduit 34 of a diameter less than the distance between opposite side walls of said cross duct. The major portion of the pipe section 34 is within and spaced from the side walls of the cross duct and extends longitudinally in said duct from the end wall 32 to a location slightly short of the right angled end 29 of said duct. The inner end 35 of the pipe section 34 opens into the cross duct 25 and is held spaced from the side walls of said duct by radial tabs 36 struck from the end of said pipe section, as best shown in FIGURE 4. To further aid in the support of the open end 35 of the pipe section 34 there is provided an angle bracket 37 welded or otherwise secured to a side wall of the cross duct 25 and to the inside of said pipe section.

Connected to the end 38 of the pipe section 34 that projects outwardly of the end wall 32 of the cross duct 25 is one end of a fresh air supply pipe 39, which has its other end extended through a wall 40 of a dwelling, as shown in FIGURE 2, for supplying fresh outside air to the heating system, there being a gate valve 41 on the outer end of the pipe 39 for closing the opening into said pipe upon cessation of suction through said pipe. A hand operated damper 42 is shown as being in the pipe section 33 exteriorly of the cross duct 25 for manually governing the flow of fresh outside air through said pipe section but could just as well be located any where in the fresh air supply pipe 39.

Also for regulating the flow of outside fresh air into the heating system is a thermostatically controlled damper 43 at a location in the pipe section 34 substantially where hot air enters the cross duct 25 from the hot air flow duct 21. The thermostat 44 for operating the damper 43 is in the cross duct 25, and is directly on the opposite side of the pipe section 34 from that where said hot air enters the cross duct, and is of the clock spring type, as more clearly shown in FIGURE 7. An inturned inner end 45 of the spiral thermostat secures the same to a pivot shaft 46 fixed to the damper 43, while the outer end 47 of said spiral thermostat lies between spaced cars 48 on the outer end of a crank arm 49 fixed to a stub shaft 50 which extends through a side wall on the cross duct and has a hand operated knob 51 on its outer end. The stub shaft 50 while appearing in the drawings to be an extension of the pivot shaft 46 is separate therefrom and is rotatable relative thereto. Thus, it can be seen that the thermostat 44 controls the position of the damper 43 in accordance with the temperature of hot air in the cross duct 25, and that the position of the crank arm 49, which is hand adjusted, controls the operation of the damper at different temperatures.

Within the cross duct 25 and directly in front and slightly spaced from the open end 35 of the fresh air pipe section 34, is a circular bafiie plate 52, which is slightly cone shape, and which has the apex thereof directed towards the open end 35 of the pipe section so as to function as an air diffuser for air leaving said pipe section. The circular outer edge of the baflie plate 52 is spaced inwardly of the side walls of the cross duct 25 so as to permit air deflected outwardly by said baffle to pass therearound and in so doing to be thoroughly mixed with hot air circulated through said cross duct. Normally the baffie plate 52 remains in a fixed position supported by an arm 53 secured to said plate and bolted, as at 54, to one side wall of the cross duct 25. However, should it be desired to decrease the restriction of air passing the baffle plate 52, said plate may be adjusted at a slight angle and with the use of the bolt and nut connection be secured against movement to the wall of the cross duct 25.

From the foregoing it is apparent that a small quantity of the heated air forced into the hot air flow duct 21 by the blower 17 in the furnace 12 for circulation through the interior of the dwelling, will enter the cross duct 25 through the small cylindrical intake pipe section 28 and flow through said cross duct, as indicated by the arrows 55 in FIGURE 3, to the cool air return duct 22 where it is returned to the furnace. This heated air in passing longitudinally along the outer side of the cylindrical wall of the fresh air supply pipe section 34 preheats the fresh air being drawn through said pipe section as indicated by the arrows 56, prior to the mixing of the fresh air with the heated air and the passing of the mixture as shown by the arrows 57, into the cool air return duct 22. If, between operations of the blower 17 or for any other reason, the temperature of hot air supplied to the cross duct 25 should fall below its effectiveness to heat properly the cold outside fresh air, the thermostat 44 will close the damper 43 so as to prevent the entrance of outside air into the heating system. Thus, it can be seen that the thermostat controlled damper 43 regulates the flow of fresh outside air into the heating system in accordance with the temperature of heated air being circulated through the system. It also will be apparent that the supplying of fresh outside air to the heating system not only provides for an exchange of air within the dwelling, but replenishes air to the interior of the dwelling for air consumed by burners and air exhausted from within the dwelling by draft diverters in stacks, clothes driers, kitchen ventilator fans, etc., thus equalizing the air pressure within the dwelling with that of outside atmospherical pressure.

In FIGURES 8 and 9 the improved air pressure equalizer is shown as being applied to a gravity warm air furnace in which a fire chamber is surrounded by an outer casing 61 and bonnet 62 so as to provide an air circulating space 63 having a lower cool air intake 64 and a plurality of upper warm air outlet pipes 65, which lead to the various rooms (not shown) of a dwelling. With this type of furnace the cross duct 25 is slightly elongated and is positioned vertically so as to have its opposite end portions in communication with the upper and the lower portions of the air circulating space 63. The short cylindrical pipe section 28 at the intake end of the cross duct 25 extend through a hole 66 and into the upper portion of the air space 63, while the right angled open end 29 of said cross duct registers with a hole 67 in the lower portion of said air space 63. Like the previously described type of furnace to which the invention was applied, the fresh outside air supply pipe 39 extends to the outer side of an outside wall 68 of a dwelling where it has thereon the gate valve 41.

Referring now to the central heating pipeless furnace, shown in FIGURE 10, it will be noted that the cross duct 25 of the improved air pressure equalizer is also arranged vertically, but is of less length than is shown in FIGURES 8 and 9. This type of furnace has a fire chamber 70 within and spaced from a shell like wall 71 suspended from a floor grate 72 and terminating short of the base of the furnace. Outward of and spaced from the shell like wall 71 is an outer casing 73 which extends between the base of the furnace and the floor grate 72. This construction provides a downward air circulating space 74 between the casing 73 and sleevelike wall 71 and extending from the peripheral portion of the grate 72 and the shortened lower end of said sleevelike wall, and an upward air circulating space 75 between said sleevelike wall and the fire chamber 70 and extending from the lower end of said shortened wall 71 to the central portion of the grate 72. In this case the cylindrical pipe section 28 at the intake end of the cross duct 25 extends through holes 76 and 77 in the outer casing 73 and sleevelike wall 71, respectively, so that its open end is positioned in the hot air space 75, while the right angled open end 29 of said cross duct registers with a hole 78 in the outer casing 73 for communication with the cool air return space 74. The fresh outside air supply pipe 39, as in the other cases, extends to the outer side of an outside wall 79 of a dwelling where it has thereon the gate valve 41.

In view of the foregoing description taken in conjunction with the accompanying drawings, it is believed that a clear understanding of the construction, operation, and advantages of the air pressure equalizer will be quite apparent to those skilled in the art of hot air heating systems. A more detailed description is accordingly deemed unnecessary.

It is to be understood, however, that even though there is herein shown and described a preferred embodiment of the invention, various changes may be made without departing from the spirit and full intendment of the invention.

What is claimed is:

1. In a hot air heating system for heating the interior of an enclosure, said system including a furnace having a heat exchanger therein, cool air duct means for supplying said heat exchanger with cool air from within said enclosure, and hot air duct means for supplying the interior of said enclosure with heated air from said heat exchanger; fresh air duct means communicating between the exterior of said enclosure and said cool air duct means for supplying the latter with fresh air from outside said enclosure; conduit means communicating between said hot air duct means and said fresh air duct means for introducing heated air to said fresh air duct means for warming fresh air therein prior to its introduction to said heat exchanger; damper means in the fresh air duct means between said conduit means and the external end of said fresh air duct means for controlling the flow of outside air into the fresh air duct means; and a thermostat control mechanism affected by temperature within said conduit means for maintaining said damper means closed when the temperature within said conduit means is lower than a selected value.

2. A heating system for enclosures as defined in claim 1 wherein there is provided a manual adjustment to the thermostat control mechanism exteriorly of the conduit means for opening said damper at a selected one of a number of different temperatures.

duct means within the conduit means through which hot I air flows prior to being mixed with air discharged from said fresh air duct means.

4. The combination with a forced hot air heating system within an enclosure for heating the interior of said enclosure, said heating system including a furnace having a combustion chamber therein, an outer casing spaced from said combustion chamber and forming an air passageway between the same and said chamber for heating air cir.-

culated through the passageway, a blower in said furnace for circulating air through said passageway, a hot air flow duct and a cool air return duct communicating with opposite ends of said passageway and with the interior of the enclosure for circulating heated air through said enclosure; of a cross duct of considerably less size than said hot air flow and cool air return ducts and in communication with said last mentioned ducts at its opposite end portions so as to bypass a small quantity of heated air from said hot air flow duct to said cool air return duct, and a fresh air supply pipe opening externally of said enclosure for supplying said cross duct with air from outside said enclosure, said outside air supply pipe having an open ended section longitudinally disposed within said cross duct by being extended through the end of said cross duct that is in communication with the hot air flow duct and opening into said cross duct adjacent the location of communication of said cross duct with said cool air return duct.

5. A heating system for enclosures as defined in claim 4 wherein there is provided a damper in the outside air supply pipe for controlling the flow of outside air into the cross duct, and a thermostat control mechanism affected by temperature within said cross duct for maintaining said damper closed when the temperature said cross duct is lower than a selected value.

6. A heating system for enclosures as defined in claim 5 wherein there is provided a manual adjustment to the thermostat control mechanism exteriorly of the cross duct for opening said damper at a selected one of a number of different temperatures.

References Cited in the file of this patent UNITED STATES PATENTS Thompson Sept. 17, 1957 

